A front-opening unified pod (FOUP) is constructed to hold semiconductor wafers securely and safely in a controlled environment. FOUPs allow wafers to be removed for processing or measurement by machines equipped with load ports and robotic handling systems. Referring to FIGS. 1 and 2, a conventional FOUP is shown at 1A. FOUP 1A includes a container 1B enclosing a volume 1C to hold the wafers. Each of the top and side surfaces 1D of the FOUP has-attached carrying handles 1E for transport and placement of the FOUP. The bottom surface of the FOUP has three point supports 1F for coupling with load ports of processing machines.
Certain processing and metrology machines require that the wafer orientation be upside down during processing. These machines have internal robots that handle the wafer to flip it for processing and then flip it back to standard orientation before returning it to the FOUP. These robots are complex and reduce the throughput of the machines because time is consumed in slowly handling and flipping each wafer. Currently, there is no bulk flipping solution.
These flipping robots induce vibration and undesirable mechanical handling, and increase the chance of wafer damage. In addition, these robots are currently unable to handle thinned wafers and would require changes in end effector designs for multiple machines including wafer thinning, backside metallization (BSM), thin film resistance (TFR), and film thickness monitor (FTM).